[FFmpeg-devel] [PATCH] fix compilation in cygwin

[Måns Rullgård]

Vitor Sessak <vitor1001 at gmail.com> writes:

> M?ns Rullg?rd wrote:
>> Michael Kostylev <michael.kostylev at gmail.com> writes:
>>
>>> On Sun Jan 10 21:55:50 2010
>>> Vitor Sessak wrote:
>>>
>>>>>> +#if !HAVE_EXP2F
>>>>>> +static av_always_inline av_const float exp2f(float x)
>>>>>> +{
>>>>>> +    return exp(x) * 0.693147180559945;
>>>>>> +}
>>>>>> +#endif /* HAVE_EXP2F */
>>>>> Same again.  exp2() should be preferred.
>>>> Let's hope that at least exp2() is supported...
>>> exp2() is missing in NetBSD and DragonFly.
>> We have a replacement for it, so it's OK.
>
> We have a replacement for log2(), but not for exp2().
>
> I'm slightly favorable of adding a replacement for exp2() (as
> attached) as we do for log2(), since we can get some speed gain in
> platforms where exp2() is supported and we'll eventually need exp2()
> sooner or later.
>
> -Vitor
> Index: configure
> ===================================================================
> --- configure	(revision 21124)
> +++ configure	(working copy)
> @@ -950,6 +950,8 @@
>      dos_paths
>      ebp_available
>      ebx_available
> +    exp2
> +    exp2f
>      fast_64bit
>      fast_cmov
>      fast_unaligned
> @@ -965,6 +967,7 @@
>      libdc1394_2
>      llrint
>      log2
> +    log2f
>      loongson
>      lrint
>      lrintf
> @@ -2370,8 +2373,11 @@
>  check_lib math.h sin -lm
>  check_lib va/va.h vaInitialize -lva
>  
> +check_func exp2
> +check_func exp2f
>  check_func llrint
>  check_func log2
> +check_func log2f
>  check_func lrint
>  check_func lrintf
>  check_func round
> Index: libavutil/internal.h
> ===================================================================
> --- libavutil/internal.h	(revision 21124)
> +++ libavutil/internal.h	(working copy)
> @@ -263,6 +263,20 @@
>      }\
>  }
>  
> +#if !HAVE_EXP2
> +static av_always_inline av_const double exp2(double x)
> +{
> +    return exp(x * 0.693147180559945);
> +}
> +#endif /* HAVE_EXP2 */
> +
> +#if !HAVE_EXP2F
> +static av_always_inline av_const float exp2f(float x)
> +{
> +    return exp2(x);
> +}
> +#endif /* HAVE_EXP2F */
> +
>  #if !HAVE_LLRINT
>  static av_always_inline av_const long long llrint(double x)
>  {
> @@ -277,6 +291,13 @@
>  }
>  #endif /* HAVE_LOG2 */
>  
> +#if !HAVE_LOG2F
> +static av_always_inline av_const float log2f(float x)
> +{
> +    return log2(x);
> +}
> +#endif /* HAVE_LOG2F */
> +
>  #if !HAVE_LRINT
>  static av_always_inline av_const long int lrint(double x)
>  {

I'm fine with this.  Please commit it so we get rid of those build
failures.

-- 
M?ns Rullg?rd
mans at mansr.com